1. Field of the Invention
The present invention relates to a semiconductor memory device.
2. Description of the Related Art
NAND flash memories are conventionally known as nonvolatile semiconductor memories. For the NAND flash memory, a method of sensing current is known as a data read method. Such a technique is disclosed in, for example, PCT National Publication No. 2006-500727.
This technique maintains the potentials of bit lines constant to reduce adverse effects of noise among the bit lines. However, to maintain the potential of the bit line constant, a cell current needs to flow from the bit line to a source line. Furthermore, according to the method of sensing current, a plurality of sensing operations are performed on the same data on the assumption that the cell current is large.